#1: Less Data, More Information: Think of maps as icing on a wedding cake, which adds to aesthetics and complements the taste, without which a cake is incomplete. A Map based visualization enriches the overall appeal and makes it easy for brain to interpret.
A simple side by side illustration here compares a KPI, e.g. GDP for different countries in a map format versus pie chart format. With all UI parameters being same, the map based visual provides more information for the same data set. This is a simple example where the map not only displays data, but provides a mechanism for us to analyze only based on the UI layout.
#2: Geo Codec Integration: Geo coding mechanisms are designed to precisely locate an area in the entire world. Initially, mankind used stars to find their position in earth, and now we rely on man made satellites to go from doorstep to neighbor’s house. Geography coding methods were slowly developed and adopted over several centuries and are available in public domain. Some popular examples are given below.
- Latitude and Longitude (e.g. -30.2214, 21.2344)
- Postal Code hierarchy (e.g. 49008-1234 in US & 600044 in India)
- WGS84 for Global Positioning System (including updated versions)
In the last decade, algorithms with fuzzy search and prediction capabilities have made inroads into all devices. This helps in refining the actual location based on few descriptive keywords as illustrated here with the Google Maps application. ETL tools have specialized modules that can parse partially complete data set and derive the geographic information.
#3: Dimensionality: This aspect is related to human perception of visualizations and dependent on the first item. If we take a step back and look at all visualization options available, it becomes evident that almost every type of chart can show only two dimensions.
There is another reason why 3-D charts did not become popular. In cases where we have X,Y & Z co-ordinates, the depth perception based on Z axis is hard for brain to interpret in a two dimensional flat surface. Human brain has evolved to look up to horizon, where sky meets the sea as a reference point for three dimensionality.
Only specialized applications rely on 3D charts, and in business intelligence arena it is not adopted in large scale. Consider a simple KPI, e.g. Sales for which we have to analyze the KPI by three different dimensions like Time, Product & Geography. In this situation the third dimension can still be represented in a two dimensional surface as represented in the thumbnail. A small disclaimer here is to note that one of the dimensions among three must be based on geography.
#4: Layering and Zoom: Map layering is a concept that helps the developer add more content and context to the visualization. This additional visual element can change perspective of the actual data being projected. User interpretation of data changes based on the layer in current viewing context. For example, in street level layer, user might scan for potential competitors in the map whereas in a topography layer, the same user will perform comparative analysis on regional performance.
Zooming is a functionality that is taken for granted today. This has redefined the concept of drill down and roll ups. Starting at world level, it is very intuitive to go down to street level and view data with high accuracy. Zoom and layers in maps work in tandem to provide a user experience that is unmatched when compared all other UI representation styles.
NOTE: Apart from the four items listed above, several refinements in data, logic and UI also contributed towards making maps one of the primary methods of representing data.